#define _CRT_SECURE_NO_WARNINGS 1
struct ListNode* trainningPlan(struct ListNode* head) {
    if (head == NULL || head->next == NULL)
        return head;
    struct ListNode* prve = NULL;
    struct ListNode* pcur = head;
    while (pcur)
    {
        struct ListNode* next = pcur->next;
        pcur->next = prve;
        prve = pcur;
        pcur = next;
    }
    return prve;
}